Warning over Hampshire and Isle of Wight icy stretches
A warning is in place for icy stretches in Hampshire and the Isle of Wight which could lead to hazardous driving conditions overnight and into Friday.
Police say further snowy weather is expected and temperatures will drop below freezing.
Nearly 1,000 schools in Hampshire and all island schools closed earlier after up to 20cm (eight inches) of snow fell.
Southampton Airport reopened at 1600 GMT but passengers were warned to expect disruption.
An airport spokeswoman said flights would be delayed on Thursday evening and Friday morning.
About 1,300 tonnes of snow had been shifted from the runway to allow flights in and out, she added.
The heaviest snowfall was seen in the Petersfield and Alresford areas, but coastal areas were also hit by as much as 12cm (five inches).
Police said driving conditions would continue to be difficult on the M3, A3, A3M and M27. Gritting and ploughing took place on priority roads throughout the day.
Hampshire Constabulary said: "The snowfall has become lighter but the warning not to take any journeys unless they are essential remains in place."
The force said further snowfalls were expected, but they would be much lighter than earlier.
"In addition, temperatures are set to drop below zero, which will cause icy roads and pavements, continuing the dangerous travelling conditions."
Extra 4x4 vehicles for emergency crews to patrol roads with Highways Agency teams were drafted in by both the military and Hampshire Fire and Rescue Service.
South West Trains (SWT) said services were running but with delays, and a revised timetable was planned for Friday.
Cross-Channel ferries from Portsmouth were running as normal.
On the Isle of Wight, all Island Line rail services and Wightbus bus services were suspended.
The island's refuse collections were postponed but Calbourne polling station opened for a by-election.
NHS Isle of Wight said outpatient appointments, the Heart Care Club, community clinics and day surgeries were all cancelled.
NHS Hampshire said residents should not venture out unless urgent but, if they did, should wear layers of warm clothes, flat shoes with a good tread, and take a walking stick to help with balance.
Dr Stuart Ward, the service's clinical director, said: "Outpatient and GP appointments for regular treatment such as cholesterol or blood pressure checks can wait until the weather improves."
Earlier, the M27 at Eastleigh and M3 near Winchester were both blocked by jack-knifed lorries in the early hours.
In Farnborough, problems were reported on the A325 and A331, while the B3006 was thought to have become impassable near its junction with the A3.